/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jena.atlas.io;

import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;

import org.apache.jena.atlas.lib.Chars;
import org.junit.jupiter.api.Test;

public class TestStreamUTF8 {
    static Charset utf8 = Chars.charsetUTF8;
    static CharsetDecoder dec = utf8.newDecoder();
    static CharsetEncoder enc = utf8.newEncoder();

    // UTF-8 encoding.
    // character '¢' = code point U+00A2 -> C2 A2
    // character '€' = code point U+20AC -> E2 82 AC

    static private final String asciiBase             = "abc";
    static private final String latinBase             = "Àéíÿ";
    static private final String latinExtraBase        = "ỹﬁﬂ";  // fi-ligature, fl-ligature
    static private final String greekBase             = "αβγ";
    static private final String hewbrewBase           = "אבג";
    static private final String arabicBase            = "ءآأ";
    static private final String symbolsBase           = "☺☻♪♫";
    static private final String chineseBase           = "孫子兵法"; // The Art of War
    static private final String japaneseBase          = "日本";    // Japanese

    @Test public void test_in_00() { testIn(""); }
    @Test public void test_in_01() { testIn(asciiBase); }
    @Test public void test_in_02() { testIn(latinBase); }
    @Test public void test_in_03() { testIn(latinExtraBase); }
    @Test public void test_in_04() { testIn(greekBase); }
    @Test public void test_in_05() { testIn(hewbrewBase); }
    @Test public void test_in_06() { testIn(arabicBase); }
    @Test public void test_in_07() { testIn(symbolsBase); }
    @Test public void test_in_08() { testIn(chineseBase); }
    @Test public void test_in_09() { testIn(japaneseBase); }

    @Test public void test_out_00() { testIn(""); }
    @Test public void test_out_01() { testOut(asciiBase); }
    @Test public void test_out_02() { testOut(latinBase); }
    @Test public void test_out_03() { testOut(latinExtraBase); }
    @Test public void test_out_04() { testOut(greekBase); }
    @Test public void test_out_05() { testOut(hewbrewBase); }
    @Test public void test_out_06() { testOut(arabicBase); }
    @Test public void test_out_07() { testOut(symbolsBase); }
    @Test public void test_out_08() { testOut(chineseBase); }
    @Test public void test_out_09() { testOut(japaneseBase); }

    static void testIn(String x) {
        try {
            byte[] bytes = stringAsBytes(x);

            ByteArrayInputStream bin = new ByteArrayInputStream(bytes);
            // Create string from bytes
            try (InStreamUTF8 r = new InStreamUTF8(bin)) {
                char[] cbuff = new char[x.length() * 10];    // Way too big
                int len = r.read(cbuff);
                String str = new String(cbuff, 0, len);
                assertEquals(x, str);
            }
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    }

    static void testOut(String x) {
        try {
            byte[] bytes = stringAsBytes(x);
            ByteArrayOutputStream bout = new ByteArrayOutputStream();
            try (Writer out = new OutStreamUTF8(bout)) {
                out.write(x);
            }
            byte[] bytes2 = bout.toByteArray();
            assertArrayEquals(bytes, bytes2);
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    }

    static byte[] stringAsBytes(String x) {
        try {
            ByteArrayOutputStream bout = new ByteArrayOutputStream();
            try (Writer out = new OutputStreamWriter(bout, utf8)) {
                out.write(x);
            }
            byte[] bytes = bout.toByteArray();
            return bytes;
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    }
}
